Image intensifier devices may be utilized in night vision goggles to amplify a low light scene to the user. Utilizing a MEMS image intensifier may enable the reduction of the size and weight of the night vision goggles. The MEMS image intensifier device may be constructed from a plurality of different wafers that are hermetically sealed to one another. In a conventional wafer construction process for a MEMS image intensifier device, a first wafer requires double sided processing, where a one of the sides of the first wafer may be required to utilize a low temperature hermetic seal to bond a second wafer to the first wafer. This low temperature hermetic seal often utilizes indium and one or more adhesion metals that underlies the indium. In conventional wafer construction processes, indium and adhesion metals are placed on a planar surface of the wafer substrate in order to achieve a low temperature hermetic seal. Indium is a very soft and tacky metal and can be easily damaged or stick to tooling. To avoid handling indium throughout the wafer production process the material is deposited late in the process onto adhesion metals on the wafer surface. Double sided wafers, however, are repeatedly handled and placed in and out semiconductor equipment (e.g., chucks, etc.) during the wafer construction process. This often results in the adhesion metals becoming scratched or damaged during the wafer construction process. Once the adhesion metals become damaged, a hermetic seal is prevented from forming due to gaps or scratches in the adhesion metals because the indium does not wet across the damaged area. Furthermore, once indium oxidizes, fresh indium must be exposed in order to provide the bonding and hermetic seal. Thus, as is often the case in conventional wafer constructions, a bonding surface of the second wafer must have protrusions in order to penetrate and expose the fresh indium disposed on the adhesion metals of the planar surface of the other wafer.
Therefore, what is needed is a process of low temperature combining/bonding of multiple wafers of a MEMS device that does not damage the adhesion metals allowing continuous patterns of Indium to form a proper hermetic seal between wafers. Furthermore, what is also needed is a process that enables double sided processing of bonded wafer pairs with low temperature bonding. What is also needed a process that hermetically seals the wafers together with a low temperature bond having a reduced seal area.